1. Field of the Invention
This invention relates to river travel and more particularly to ramps for traversing river dams to provide for hovercraft passage.
2. Description of the Prior Art
Navigable rivers and other water ways have been extensively used for transportation and geographical areas proximate to such water ways have enjoyed rapid development. The rivers of the United States today are used extensively for transportation of bulk materials such as coal, gravel, bulk chemicals and raw materials for industry. The bulk cargoes are particularly adaptable for river transportation due to the large capability of barges and tankers which far exceed trucks, railroad cars and most other overland methods of transportation.
Althrough river transportation as a public convenience was used in the past, such use for extensive or even community travel has fallen in disuse since the development of rapid land travel vehicles, such as buses, subways and trains. Presently the overland vehicles are much faster than river transportation.
The duration of river travel time between two points is substantially lengthened due to dams along the water ways. The dams are necessary to provide adequate channel depth and for flood control. Thus it is necessary for a river conveyance to travel through a series of locks to pass the dam and move from one river level to the next. The lock system of traversing dams, although widely accepted, causes considerable delays in the travel along a river.
Very recently boats which travel on a cushion of air have been used for both water and land travel. These boats, generally known as hovercraft or air cushion boats, have a capacity of about fifty people and are an acceptable public conveyance for commuting short distances, such as one hundred miles or less. However, when rivers are used as a suppport for the hovercraft, it is necessary to encounter time delays due to travel through dam locks. The hovercraft are supported on a cushion of air produced by downwardly directed fans or blowers. The air boats are propelled by an aircraft engine which also can provide the cushion of air on which they travel. Various hovercraft have been used on some bodies of water where there are large distances without locks, such as Lake Michigan and the English Channel. However, their use on numerous rivers of the United States have been severely restricted due to their inability to travel rapidly over the numerous dams.
In accordance with the present invention, an apparatus for the traversal of dams by hovercraft is provided which is much faster than passing the craft through a lock.